The present invention relates to a control system, particularly to a control system for controlling an object to be controlled with an A.C. biased in-put supply to a switching element.
One of the objects of the present invention is to provide a control system with an A.C. biased in-put supply to a switching element which is characterized in that the system is constructed in such a manner that an object to be controlled is connected with the out-put a switching element of a bi-stable multi-vibrator, while to the in-put of the bi-stable multi-vibrator an A.C. biased in-put signal mixed with an A.C. signal presenting a higher frequency than that of an in-put signal is given.
Another object of the present invention is to use the above-mentioned control system for controlling rotation speed of a motor.
Features of the present invention lie in that the bi-stable multi-vibrator comprises a flip-flop circuit, that the bi-stable multi-vibrator comprises a Schmitt circuit, that the control system comprises a thermal compensator, that the control system comprises a compensating means for compensating variations in the power supplied to the system, that control system comprises a variable element for varying the mode of the control, and that the motor is an A.C. motor with A.C. supply as well as a D.C. motor with D.C. supply.
The main advantage of the present invention is that the power consumption is greatly reduced and a precise control of an object such as a motor is assured.